The invention relates to a folding top for convertible vehicles of the type having a foldable frame supporting a flexible top cover which top can be selectively moved between an in-use closed position to a folded down stowed position.
German Patent 3,8l8,616 has already disclosed a folding top of this general type, the top cover being secured along the whole length of its terminating edges adjoining the rear of the side windows on retention rails which form part of the lateral top pillars of the main strut. To the side and behind the retention rails, the top cover is held by a U-shaped material retaining hoop which forms the lower termination of the folding top and is slidably articulated on its lateral legs on the associated top support pillar of the main strut.
In a top cover border region which includes the lower terminating edge and extends from the retention rail approximately as far as the longitudinal center of the associated leg of the material retaining hoop, no permanently operative fastening of the top cover to the profile of the material retaining hoop is provided. On the contrary, the border region is only pulled against the shaping periphery of the material retaining hoop, via a strap of rubber-elastic material, during the closure of the cover, the border region of the top cover thereby remaining tautly stretched with the top closed. For this purpose, one end of the strap is secured on the top cover, after which it enfolds a deflection hoop on the leg of the material retaining hoop. The other end of the strap is articulated on the lateral leg of a corner strut which can be raised automatically into its designed position during the closure of the top. Due to the change in the spacing of the articulation point for the strap relative to the leg of the material retaining hoop, the required tensioning advance of the strap can take place automatically.
Top concepts are also known in which the material retaining hoop is articulated directly on the associated top support pillar of the main strut by the forward ends of its lateral legs. Since there is no need here for any longitudinal displaceability of the material retaining hoop relative to the articulation point on the top support pillar, the top cover can be secured on the profile of the material retaining hoop all the way along its lower terminating edge, as far as the region of the joint. In front of the region of the joint, however, no permanent fastening of the top cover on the top support pillar is possible since the top cover stretched taut along the lower terminating edge would lead to blocking of the swinging of the material retaining hoop and opening of the top would not be readily possible.
In addition, fixing via straps which is operative only with the top closed, as known from German Patent 3,818,616, is not readily achievable with these border regions which include a lower length of the terminating edges extending along the top support pillars. This is all the more true if the corner strut is attached to the top frame near to the region of the joint which results in an insufficient change in the spacing of the lateral legs of the corner strut relative to the border regions during the erection of the folding top.
An object on which the invention is based is to modify a folding top of the generic type such that fixing of border regions which is operative only with the top closed is made possible via tie means which are situated in a lower region of the length of the terminating edges extending along the top support pillars.
This object is achieved according to preferred embodiments of the present invention by providing a folding top for convertibles comprising a top cover which can be stretched over a supporting top frame and is held along its lower terminating edge by a U-shaped material retaining profile and along its rear terminating edges, which adjoin the side windows, by lateral top support pillars of a main strut, the main strut being attached to the bodywork of the vehicle via its pivotably mounted top support pillars, having intermediate support for the top cover in a transverse plane between the material retaining hoop and the main strut by means of a U-shaped corner strut, the lateral legs of which corner strut are articulated on associated frame members, and having fixing of lateral border regions of the top cover on the associated frame member via first tie members, the first tie members connecting the terminating edges of border regions to the associated leg of the corner strut while being deflected at the frame member to pull the border region towards the frame member when the top is closed by virtue of the swinging of the corner strut relative to the material retaining profile, wherein the border regions to be fixed are held by the top support pillars of the main strut, the border regions including a lower length of the terminating edges of the top cover which extend along the top support pillars, and wherein the first tie members, starting from their deflection on the associated top support pillar, first of all extend rearwards towards a deflection point on the material retaining profile, which deflection point is offset rearwards relative to the pivot axis of the corner strut, and after enfolding the deflection point, they extend forwards towards their holding point on an associated leg of the corner strut.
In order to achieve favorable lever ratios for a corner strut articulated close to the border regions, the longitudinal center axes of the lateral legs of the corner strut and the directions of tension of the tie members extend relative to one another in a manner similar to the sides of an equilateral triangle, according to certain preferred embodiments of the invention.
The pivoting advance of the corner strut can simultaneously be used in an advantageous manner to fix corresponding border zones of an inner lining of the top cover via further tie members.
For reasons of durability, textile and thus flexible straps, which stretch only a little under tensile stress, are particularly suitable as the tie means.
To compensate for tolerances and to permit readjustment of the straps, these are preferably however of adjustable length.
Adjustment of the length of the strap is particularly simple if a loop at one end of the strap can be fixed in a variable manner via a velcro-type fastener according to especially preferred embodiments of the invention.
Essentially U-shaped hoops which are bent from rigid round wire and can thus be produced at a favorable cost are provided for the deflection of the strap.
Preferably only one holder, which serves for the connection of the strap associated with the top cover and for the deflection of the strap associated with the inner lining, is arranged on each of the two legs of the corner strut.
This holder too can be formed at a favorable cost from bending wire. The one-piece nature of the holder is also particularly expedient because it is thereby possible to guarantee precise spacing between the deflection point and the connection point. Due to the adjustability of the length of the straps, the holder can be connected to the corner strut without problems by welding or the like, providing weight and cost advantages.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.